Divert Landline to Mobile: Dial *21*[mobile]# (UK Guide 2026)
Quick answer: To divert all calls from a UK landline to your mobile, pick up your landline handset and dial *21* followed by your mobile number, then #. For example: *21*07700900123#. You'll hear a confirmation tone. To cancel, dial #21#. This universal code works on most UK landline providers including BT, Sky, TalkTalk, and Plusnet. Virgin Media uses a different method — see the provider-specific table below.
How Do I Divert Calls From My Landline to My Mobile UK?
Call diverting (also called call forwarding) sends incoming landline calls to another number — typically your mobile. It's useful when you're away from the office, working remotely, or transitioning between premises. Here's how to set it up in three steps:
- Pick up your landline handset and wait for a dial tone.
- Dial
*21*[your mobile number]#— for example,*21*07700900456#. - Listen for the confirmation tone (usually three beeps or a recorded message). Your landline calls will now forward to your mobile.
To cancel call diversion, pick up the handset and dial #21#. You'll hear a confirmation tone confirming the divert has been removed.
What Are the Call Divert Codes for Each UK Provider?
While *21* is the standard code across most providers, there are differences — particularly with Virgin Media, which runs on its own network. Here's a complete breakdown:
| Provider | Divert All Calls | Cancel Divert | Divert If No Answer | Monthly Cost |
|---|---|---|---|---|
| BT | *21*[mobile]# |
#21# |
*61*[mobile]# |
Free to set up; diverted calls charged at local/national rate |
| Sky | *21*[mobile]# |
#21# |
*61*[mobile]# |
Free to set up; per-minute charges apply |
| Virgin Media | *21*[mobile]# or via My Virgin Media app |
#21# |
*61*[mobile]# |
Free to set up; diverted calls charged per minute |
| TalkTalk | *21*[mobile]# |
#21# |
*61*[mobile]# |
Free to set up; standard call charges |
| Plusnet | *21*[mobile]# |
#21# |
*61*[mobile]# |
Free to set up; per-minute charges apply |
Important: With every provider listed above, you'll be charged for the diverted leg of the call. This means each forwarded call costs you a landline-to-mobile rate — typically 10p–16p per minute depending on your tariff. For a business receiving 30+ calls per day, this can add up to £100–£200+ per month in divert charges alone.
Does Call Divert Show My Landline Number or My Mobile Number?
This is a common concern for businesses. When you use traditional call diverting, the caller will see your landline number when they dial it — but if you need to call them back from your mobile, your mobile number is displayed instead. This creates an inconsistent, unprofessional experience. There is no way to change this with standard landline call diversion.
We recommend businesses that rely on returning calls from mobiles consider a VoIP (cloud phone) system, which solves this problem entirely.
Why Is a Cloud Phone System Better Than Call Diverting for Businesses?
Traditional call diverting is a quick fix — it was designed for occasional use, not as a permanent business communication solution. If you're diverting calls regularly, you're likely paying more and getting less functionality than a modern hosted VoIP system would provide.
Here's a direct comparison:
| Feature | Landline Call Divert | Hosted VoIP (Cloud Phone) |
|---|---|---|
| Calls ring on mobile | ✅ Yes | ✅ Yes — plus desk phones, laptops, tablets |
| Keep your landline number | ✅ Yes | ✅ Yes — number porting included |
| Show landline number on outbound calls | ❌ No — shows your mobile number | ✅ Yes — always displays your business number |
| Auto-attendant / IVR | ❌ No | ✅ Yes — "Press 1 for Sales, 2 for Support" |
| Ring multiple team members | ❌ No — one number only | ✅ Yes — hunt groups, ring all, sequential ring |
| Call recording | ❌ No | ✅ Yes — included or add-on |
| Voicemail to email | ❌ No | ✅ Yes |
| Typical monthly cost | £20–£50+ in landline rental + per-minute divert charges | From £6–£15 per user/month including calls |
Our recommendation: If you're diverting calls from a landline to a mobile more than occasionally, a hosted VoIP phone system is the better long-term solution. It costs less, does more, and presents a professional image to every caller. You keep your existing landline number, your business number shows on all outbound calls, and your team can answer from anywhere — mobile, laptop, or desk phone.
How Do I Divert Only Unanswered Calls to My Mobile?
If you want your landline to ring first and only forward to your mobile when nobody picks up, use the "divert on no answer" code instead:
- Pick up your landline handset.
- Dial
*61*[your mobile number]#— for example,*61*07700900456#. - Wait for the confirmation tone.
Your landline will ring for approximately 15–25 seconds (varies by provider) before forwarding to your mobile. To cancel, dial #61#.
There's also a "divert when busy" option: dial *67*[your mobile number]#. This only diverts when your line is engaged. Cancel with #67#.
Will Call Diverting Still Work After the UK PSTN Switch-Off?
The traditional Public Switched Telephone Network (PSTN) is being retired across the UK, with Openreach and other providers migrating all landlines to digital (VoIP) by the end of 2027. During and after this transition:
- Star codes like *21* may still work on many digital landline services, but this is not guaranteed across all providers.
- Some providers are moving to app-based or online portal controls for call management features, making dial codes redundant.
- If your landline is migrated to a basic digital voice service, you may lose features like call divert entirely unless you upgrade.
We recommend: Rather than waiting to see whether your call divert features survive the digital switchover, now is the ideal time to move to a hosted VoIP system. You'll future-proof your business communications, retain your existing number, and gain far more functionality at a comparable or lower cost.
Frequently Asked Questions
Is there a charge for diverting landline calls to a mobile in the UK?
Yes. While setting up the divert is free, you'll be charged for each diverted call at your provider's landline-to-mobile rate — typically 10p–16p per minute. These charges apply on top of your normal line rental. For businesses with high call volumes, a hosted VoIP system is usually cheaper overall.
Can I divert a BT landline to a mobile permanently?
Yes, dialling *21*[mobile number]# from a BT landline will divert all calls until you manually cancel it with #21#. There's no automatic expiry. However, you'll pay per-minute divert charges on every forwarded call, which makes this expensive as a permanent solution.
Will the caller know my calls are being diverted?
No. The caller dials your landline number as normal and won't hear any indication that the call is being diverted. However, there may be a slightly longer connection time, and if you call them back, they'll see your mobile number — not your landline number.
Can I divert my landline to a mobile using my provider's app?
Some providers — including Virgin Media and BT — offer call management through their online accounts or apps. However, functionality varies and is often limited compared to a dedicated business phone system. If you need reliable, flexible call routing, a hosted VoIP platform gives you full control via a web portal and mobile app.
What's the difference between call diverting and a hosted VoIP system?
Call diverting is a basic feature that redirects calls from one number to another. A hosted VoIP system replaces your landline entirely — your calls arrive via the internet to any device (mobile, laptop, desk phone), your business number shows on outbound calls, and you get features like auto-attendant, call recording, ring groups, and voicemail-to-email. Most businesses find VoIP costs less than a landline with regular call diverting.
